This invention relates to an apparatus for cooling integrated circuit chips and, in particular, to a liquid cooled plate which could contact the upper surface of a chip to directly remove heat.
Integrated circuit chips mounted in an array on substrates present special cooling difficulties. Although chip size has decreased and power usage is more efficient than in the past, the practice of mounting multiple, closely spaced chips on substrates has required that more emphasis be placed on cooling systems to remove the relatively high density power dissipated by the chips. Liquid coolants are commonly employed in such high density applications.
Various system have been disclosed in the prior art for providing a separate cooling member. Some of these utilize bellows-type liquid cool structures as exemplified by U.S. Pat. No. 4,977,443. However, such types of systems suffer in that they generally do not provide the large surface area required for high heat transfer rates. Other systems have attempted to utilize fins, channels or other structures in order to increase heat transfer area. U.S. Pat. No. 3,524,497 is one example which utilizes studs mounted in a liquid cooled structure for semiconductors. Another system, which utilizes microchannels, is exemplified by U.S. Pat. No. 4,758,926. A recent system disclosed in U.S. Pat. No. 4,964,458 to Flint et al., assigned to the assignee of the instant invention, uses a flexible sheet having a thermally conductive fin assembly extending normally from the sheet. The coolant flow in this fin type cooling system, as in other fin type systems, is in the same direction as the fins.
Japanese patent publication No. 57-96557 discloses another system which utilizes a series of baffle plates in an attempt to improve the efficiency of cooling by lengthening the flowing distance of the cooling medium. While this approach has some merit, the design is quite complex and expensive to fabricate. Other problems with prior art systems have been high pressure drop in the cooling medium utilized, and lack of uniformity of heat removal.
Bearing in mind the problems and deficiencies in the prior art, it is therefore an object of the present invention to provide a high performance cooling apparatus for integrated circuit chips mounted on a substrate.
It is another object of the present invention to provide an integrated chip cooling apparatus which provides uniformly high rates of heat removal.
It is still another object of the present invention to provide a cooling apparatus which is in close contact with the integrated circuit chips to remove heat therefrom.
It is a further object of the present invention to provide an efficient cooling apparatus for integrated circuit chips in which the coolant does not undergo high pressure drop.
It is yet another object of the present invention to provide a cooling apparatus which is in the form of a plate which may be placed over an integrated circuit chip heat transfer module.
It is a further object of the present invention to provide a cooling apparatus which meets the above objects and which is relatively inexpensive and easy to manufacture.